Particulate monitor

ABSTRACT

A particulate monitor includes a housing, an air-moving device coupled to the housing, and an air passageway disposed at least partially within the housing. The air-moving device is operable to create an airflow through the air passageway. The particulate monitor may include a real-time measuring device positioned at least partially within the housing and in fluid communication with the air passageway and a particulate collection device positioned at least partially within the housing and in fluid communication with the air passageway. A collection device may be positioned downstream of the real-time measuring device. At least one impactor may be movably coupled to the housing to be movable between a first position adjacent the air passageway and a second position displaced from the air passageway.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. Ser. No. 11/846,131, filed Aug.28, 2007 now U.S. Pat. No. 7,631,568, the disclosure of which isincorporated by reference in its entirety herein.

FIELD OF THE INVENTION

The present invention relates to particulate monitors, and moreparticularly to indoor air quality monitors.

BACKGROUND OF THE INVENTION

Some conventional indoor air quality (“IAQ”) monitors typically includea housing, a filter cassette or cartridge within the housing, a pumpoperable to draw an airflow through the filter cartridge, and a singleimpactor positioned adjacent an inlet to an air passageway in thehousing upstream of the filter cartridge. Impactors are typicallyconfigured to trap or filter particulates having a particular nominalsize or greater (e.g., 10 microns or greater) to substantially preventsuch particles from entering the air passageway and being collected inthe filter cartridge. The single impactor is typically removable fromthe housing and can be replaced with another single impactor of adifferent size to trap or filter different-size particulates. Otherconventional IAQ monitors include a real-time measuring system (e.g., anoptical engine), rather than the filter cartridge, to immediatelydisplay the results of an indoor air quality test.

SUMMARY OF THE INVENTION

By changing out individual single impactors in typical IAQ monitors, onemay collect samples comprised of different ranges of nominal sizes ofparticulates (e.g., samples of particulates having a nominal size of 10microns or smaller, samples of particulates having a nominal size of 2.5microns or smaller, etc.). With this information, one can isolatespecific health concerns that might be caused by a particularly highconcentration of particulates within a particular range of nominalsizes. However, changing out individual single impactors in preparationfor sample collection in typical IAQ monitors can be cumbersome and timeconsuming.

The present invention provides, in one aspect, a particulate monitorincluding a housing, an air-moving device coupled to the housing, and anair passageway disposed at least partially within the housing. Theair-moving device is operable to create an airflow through the airpassageway. The particulate monitor also includes a real-time measuringdevice positioned at least partially within the housing and in fluidcommunication with the air passageway and a particulate collectiondevice positioned at least partially within the housing and in fluidcommunication with the air passageway. The collection device ispositioned downstream of the real-time measuring device.

The present invention provides, in another aspect, a particulate monitorincluding a housing, an air-moving device coupled to the housing, and afirst air passageway disposed at least partially within the housing. Theair-moving device is operable to create an airflow through the first airpassageway. The particulate monitor also includes a first impactorcoupled to the housing and a second air passageway at least partiallycontaining therein the first impactor. The second air passageway isselectively fluidly communicable with the first air passageway. Theparticulate monitor further includes a second impactor coupled to thehousing and a third air passageway at least partially containing thereinthe second impactor. The third air passageway is isolated from thesecond air passageway and selectively fluidly communicable with thefirst air passageway.

The present invention provides, in yet another aspect, a particulatemonitor including a housing, an air-moving device coupled to thehousing, and an air passageway disposed at least partially within thehousing. The air-moving device is operable to create an airflow throughthe air passageway. The particulate monitor also includes at least oneimpactor movably coupled to the housing to be movable between a firstposition adjacent an inlet to the air passageway and a second positiondisplaced from the inlet of the air passageway.

Other features and aspects of the invention will become apparent byconsideration of the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a particulate monitor of thepresent invention.

FIG. 2 is a rear perspective view of the particulate monitor of FIG. 1.

FIG. 3 is an enlarged, exploded top perspective view of a portion of theparticulate monitor of FIG. 1, illustrating a rotatable turret, aplurality of impactors coupled to the turret, and a cap coupled to theturret to at least partially cover the impactors.

FIG. 4 a is an enlarged, exploded top perspective view of the turret andcap shown in FIG. 3.

FIG. 4 b is an enlarged, exploded top perspective view of the turret anda bottom perspective view of the cap shown in FIG. 3, illustrating theinterior of the cap.

FIG. 5 is a rear, partial cutaway view of the particulate monitor ofFIG. 1, illustrating the cap and turret rotated to a first position.

FIG. 6 is a rear, partial cutaway view of the particulate monitor ofFIG. 1, illustrating the cap and turret rotated to a second position.

FIG. 7 is a rear, partial cutaway view of the particulate monitor ofFIG. 1, illustrating the cap and turret rotated to a third position.

FIG. 8 is a rear, partial cutaway view of the particulate monitor ofFIG. 1, illustrating the cap and turret rotated to a fourth position.

FIG. 9 is a partial cross-sectional view of the particulate monitor ofFIG. 1 through line 9-9 in FIG. 1.

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate a particulate monitor or an IAQ monitor 10utilized to collect data on the quantity and sizes of airborneparticulates in a particular working space or environment to determineindoor air quality. The monitor 10 includes a housing 14, a displayscreen 18 on the front of the housing 14, and a plurality ofuser-manipulated controls 22 on the front of the housing 14 below thedisplay screen 18 (see FIG. 1). With reference to FIG. 2, the monitor 10also includes an access panel 26 removably coupled to the housing 14 foraccess to the interior of the housing 14. In the illustratedconstruction of the monitor 10, the access panel 26 incorporates aresiliently-deformable connector (e.g., a resilient tab, not shown) toengage a corresponding flat or edge on the housing 14. Alternatively,the access panel 26 may be secured to the housing 14 by conventionalfasteners, hinges, or the like. The monitor 10 also includes a pluralityof rubber or plastic plugs 30, each configured to prevent access to anelectrical connector (e.g., a power inlet, a data transfer outlet, etc.)positioned behind the plug 30.

With reference to FIG. 1, the monitor 10 also includes a cover 34coupled to the housing 14, and a rotatable impactor assembly 38protruding from the cover 34. The monitor 10 includes an air passageway42 within the housing 14, the inlet 44 of which is exposed to the bottomof the cover 34 beneath the rotatable impactor assembly 38 (see FIG. 5).With reference to FIG. 5, the monitor 10 includes a real-time measuringdevice 46 in the form of an optical engine 46 in fluid communicationwith the air passageway 42. As will be discussed in greater detailbelow, the optical engine 46 projects a laser through the air passageway42 to collect data on the quantity and sizes of particulate matterentrained in an airflow passing through the passageway 42. Such anoptical engine 46 is manufactured by Quest Technologies, Inc ofOconomowoc, Wis.

With continued reference to FIG. 5, the monitor 10 also includes aparticulate collection device 50 positioned downstream of the measuringdevice 46 and in fluid communication with the air passageway 42. In theillustrated construction of the monitor 10, the particulate collectiondevice 50 is in the form of a cylindrical, gravimetric filter cartridge50 having a filter element 54 disposed therein. As will be discussed ingreater detail below, particulate matter is collected on the filterelement 54 after being measured by the optical engine 46 for subsequentanalysis in a laboratory. As such, the filter cartridge 50 is removablethrough the access panel 26. Such a filter cartridge 50 is manufacturedby SKC, Inc of Eighty Four, Pa. or Millipore Corporation of Billerica,Mass., and are available in a number of different standard sizes (e.g.,25 mm, 37 mm, etc.). Further, in an alternative construction of themonitor 10, the filter cartridge 50 may be disposed at least partiallyoutside of the housing 14 to facilitate removal of the filter cartridge50 from the housing 14. In the illustrated construction of the monitor10, and in the alternative constructions described above, no portion ofthe filter cartridge 50 is positioned upstream of the measuring device46.

With continued reference to FIG. 5, the air passageway 42 is defined bymultiple components within the housing 14. In the illustratedconstruction of the monitor 10, the air passageway 42 is partiallydefined by the interior space 58 of the optical engine 46 through whichthe entrained particulate matter passes with the airflow, and respectiveinlet and outlet conduits 62, 66 extending from an upper surface of theoptical engine 46 and a lower surface of the optical engine 46. The airpassageway 42 is also partially defined by a conduit 70 integrallyformed with the cover 34 and another conduit 74 (e.g., a plastic tube orhose) coupling the conduit 70 and the inlet conduit 62 on the opticalengine 46. In the illustrated construction of the monitor 10, the inlet44 of the air passageway 42 coincides with the inlet of the conduit 70.

The air passageway 42 is also partially defined by the interior space 78of the filter cartridge 50 and respective inlet and outlet conduits 82,86 extending from an upper surface of the filter cartridge 50 and alower surface of the filter cartridge 50. In the illustratedconstruction of the monitor 10, the inlet conduit 82 on the filtercartridge 50 is sized to at least partially receive therein the outletconduit 66 on the optical engine 46. Specifically, the inner diameter ofthe inlet conduit 82 and the outer diameter of the outlet conduit 66 aresized to allow the outlet conduit 66 of the optical engine 46 to beinserted within the inlet conduit 82 of the filter cartridge 50. As aresult, the filter cartridge 50 may be removably coupled to the opticalengine 46 by the slip-fit between the inlet conduit 82 of the filtercartridge 50 and the outlet conduit 66 of the optical engine 46.

With continued reference to FIG. 5, the monitor 10 further includes anair-moving device 90 operable to create an airflow through the airpassageway 42. In the illustrated construction of the monitor 10, theair-moving device 90 is in the form of a diaphragm pump 90 having aninlet 94 and an outlet 98. Such a pump 90 is manufactured by UNOInternational, Ltd. of London, United Kingdom. A connecting conduit 102(e.g., a plastic tube or hose) is utilized to fluidly communicate theair passageway 42 and the pump 90. The conduit 102 may be sized toprovide a slip-fit between the connecting conduit 102 and the outletconduit 86 of the filter cartridge 50 so that the connecting conduit 102may be removably coupled to the filter cartridge 50. The housing 14includes a plurality of outlet openings 106 formed therein to fluidlycommunicate the interior of the housing 14 with the outside environmentof the monitor 10. As will be explained in greater detail below, theairflow discharged by the pump 90 into the interior of the housing 14may be exhausted through the outlet openings 106 in the housing 14.

With reference to FIG. 3, the components of the impactor assembly 38 areshown. In the illustrated construction of the monitor 10, the impactorassembly 38 includes a movable platform 110 in the form of a rotatableturret 110 supporting a plurality of impactors 114 a, 114 b, 114 cthereon. The turret 110 is rotatable about a central axis 118 and iscoupled to the cover 34 for rotation about the central axis 118. In theillustrated construction of the monitor 10, a threaded insert 122 ismolded into the cover 34, and a fastener 126 is threaded into the insert122 to secure the turret 110 to the cover 34 yet allow rotation of theturret 110 with respect to the cover 34 and housing 14. A compressionspring 128 is positioned between the fastener 126 and the turret 110 todownwardly bias the turret 110. Alternatively, other structure may beutilized to rotatably couple the turret 110 to the cover 34 and housing14. Further, in an alternative construction of the monitor 10, themovable platform 110 may be configured as an axially-slidable member,rather than the rotatable turret 110.

With reference to FIGS. 4 a and 4 b, the illustrated turret 110 includesfour apertures 130 a-130 d therethrough, each spaced a substantiallysimilar radial distance from the central axis 118, and each spaced anequi-angular distance (e.g., 90 degrees) from one-another. Particularly,the apertures 130 a-130 d are spaced from the central axis 118 by thesame radial distance as the inlet 44 of the air passageway 42, such thatany one of the apertures 130 a-130 d may be aligned with the inlet 44 ofthe air passageway 42 depending upon the rotational position of theturret 110. With reference to FIGS. 5-8, the bottom of the turret 110includes respective raised surfaces 132 a-132 d surrounding therespective apertures 130 a-130 d that selectively engage a depression133 in the cover 34 surrounding the inlet 44 of the air passageway 42.The spring 128 (see FIG. 3) biases the turret 110 toward the cover 34such that the respective raised surfaces 132 a-132 d serve as locatingfeatures for the respective apertures 130 a-130 d in the turret 110. Ofcourse, other locating features can also be used.

With reference to FIGS. 4 a and 4 b, the impactors 114 a-114 c arepositioned adjacent the respective apertures 130 a-130 c in the turret110, while the aperture 130 d is not associated with an adjacentimpactor. In the illustrated construction of the monitor 10, each of theimpactors 114 a-114 c includes a respective platform 134 a-134 c and apedestal 138 a-138 c supporting the platforms 134 a-134 c above theturret 110. Although the illustrated pedestals 138 a-138 c aresubstantially similar to one another, the respective platforms 134 a-134c are differently sized to provide different levels of particulatematter filtration to the airflow entering the air passageway 42. Forexample, the impactor 114 a may be sized to trap or filter particulatematter in the airflow leading to the air passageway 42 having a nominalsize of 1 micron or greater, while the other impactors 114 b, 114 c maybe sized to trap or filter particulate matter in the airflow leading tothe air passageway 42 having a nominal size of 2.5 microns or greater,and 10 microns or greater, respectively. As such, the impactor 114 c ismore of a “coarse” filter than the impactor 114 a. The filtrationprocess is discussed in more detail below. Although the illustratedturret 110 incorporates only three impactors 114 a-114 c, an alternativeconstruction of the monitor 10 may incorporate more or less than threeimpactors, each associated with a respective aperture in the turret 110.Alternatively, differently-sized impactors may be substituted for thoseshown (e.g., an impactor sized to trap or filter particulate matter inthe airflow leading to the air passageway 42 having a nominal size of 4microns or greater.)

With continued reference to FIGS. 4 a and 4 b, the rotatable impactorassembly 38 also includes a cap 142 coupled to the turret 110 to atleast partially cover or enclose the impactors 114 a-114 c. In theillustrated construction of the monitor 10, resiliently-deformableconnectors 146 are utilized to secure the cap 142 to the turret 110.Although the connectors 146 are shown extending from the turret 110, theconnectors 146 may alternatively extend from the cap 142 to engage theturret 110. As a further alternative, the cap 142 may be coupled to theturret 110 using conventional fasteners or the like.

With reference to FIG. 4 a, the cap 142 includes three apertures 150a-150 c that, when the cap 142 is coupled to the turret 110, aresubstantially aligned with the respective impactors 114 a-114 c on theturret 110. As a result, the apertures 150 a-150 c in the cap 142 areoffset from the apertures 130 a-130 c in the turret 110. The cap 142includes an additional aperture 150 d that is aligned with the aperture130 d in the turret 110 not associated with an adjacent impactor. Withreference to FIG. 4 b, the cap 142 includes four cylindrical walls orconduits 154 a-154 d, associated with the respective apertures 150 a-150d in the cap 142, extending toward the turret 110. Each of the conduits154 a-154 d defines a passageway 158 a-158 d therein to communicateairflow entering the respective passageways 158 a-158 d via theapertures 150 a-150 d to the air passageway 42.

As shown in FIGS. 5-8, each of the conduits 154 a-154 d includes a lowerend 162 a-162 d engaged with the turret 110, such that the passageways158 a-158 d defined by the conduits 154 a-154 d are separated andisolated from one another. With reference to FIG. 5, the impactor 114 ais contained within the passageway 158 a in the cap 142, and theaperture 130 a in the turret 110 provides an outlet for the passageway158 a. Likewise, the impactor 114 b is contained within the passageway158 b in the cap 142, and the aperture 130 b in the turret 110 providesan outlet for the passageway 158 b (see FIG. 6). The impactor 114 c iscontained within the passageway 158 c in the cap 142, and the aperture130 c provides an outlet for the passageway 158 c (see FIG. 7). As shownin FIG. 8, the aperture 130 d in the turret 110 provides an outlet forthe passageway 158 d.

With reference to FIGS. 3 and 9, the monitor 10 includes other real-timemeasuring devices 166 a-166 c, in addition to the optical engine 46,coupled to the housing 14. In the illustrated construction of themonitor 10, the measuring devices 166 a-166 c include a carbon dioxidesensor 166 a, a toxic gas (e.g., carbon monoxide, hydrogen sulfide,sulfur dioxide, nitrogen oxides, and nitrogen dioxide) sensor 166 b, anda photoionization detector (“PID”) 166 c. The carbon dioxide sensor 166a is configured to detect by diffusion the amount of carbon dioxidepresent in an airflow over the sensor 166 a. Such a sensor 166 a ismanufactured by City Technology Ltd. of Hampshire, United Kingdom.Likewise, the toxic gas sensor 166 b is configured to detect bydiffusion the amount of carbon monoxide or other toxic gases present inan airflow over the sensor 166 b. Such a sensor 166 b is manufactured byDr. Alan Doncaster of Witham, United Kingdom. The PID 166 c isconfigured to detect by diffusion the amount of volatile organiccompounds (“VOCs”, e.g., caulks, glues, etc.) present in an airflow overthe PID 166 c. Such a PID 166 c is manufactured by Ion Science Ltd. ofCambridge, United Kingdom. Additionally, other sensors or detectors maybe incorporated with the devices 166 a-166 c or separately (e.g., atemperature sensor, a humidity sensor, etc.). The illustrated monitor 10also includes such temperature and humidity sensing capabilities.

With continued reference to FIG. 9, the monitor 10 includes anair-moving device 178 in the form of an axial-flow fan 178 coupled tothe housing 14 and positioned adjacent the group of devices 166 a-166 c.Such an axial-flow fan 178 is manufactured by ADDA Corporation ofTaiwan. Specifically, the fan 178 and devices 166 a-166 c are supportedon a printed circuit board (“PCB”) 182 coupled to the housing 14. Thefan 178 is electrically connected to the PCB 182 to receive powertherefrom, and the devices 166 a-166 c (an other sensors such astemperature and humidity sensors) are electrically connected to the PCB182 to receive power therefrom and transmit the output of each of thedevices 166 a-166 c to a microprocessor (not shown) in a conventionalmanner.

The cover 34 and the PCB 182 define therebetween an air passageway 186separate and distinct from any of the other air passageways 42, 158a-158 d in the monitor 10. As shown in FIGS. 1-3 and FIG. 9, the cover34 includes a plurality of inlet openings 190 adjacent the impactorassembly 38 to allow an airflow to enter the passageway 186. The PCB 182includes a cutout 194 beneath the fan 178 to allow the fan 178 todischarge the airflow in the passageway 186 into the interior of themonitor housing 14. As will be discussed in greater detail below, theairflow discharged by the axial fan 178 into the interior of the housing14 via the cutout 194 in the PCB 182 may be exhausted through the outletopenings 106 in the housing 14 (see FIG. 9).

Before using the monitor 10, the cap 142 is removed from the turret 110to apply an adhesive or gel substance (e.g., petroleum jelly) on therespective platforms 134 a-134 c of the impactors 114 a-114 c, in aconventional manner, to catch or trap particulate matter of a desirednominal size or greater before entering the air passageway 42 formeasurement by the optical engine 46 and subsequent collection by thefilter cartridge 50. After the adhesive or gel substance is applied toall of the impactors 114 a-114 c, the cap 142 may be replaced onto theturret 110, and the impactor assembly 38 may be moved (e.g., rotated) toalign the respective aperture 130 a-130 c associated with the intendedimpactor 114 a-114 c to be used with the inlet 44 of the air passageway42.

Operation of the monitor 10 is described below with reference to FIG. 5,which illustrates the impactor assembly 38 “dialed” to the position ofimpactor 114 a. However, operation of the monitor 10 is substantiallysimilar when the impactor assembly 38 is dialed to the position of anyof the other impactors 114 b, 114 c. During an IAQ test, the pump 90 isoperated to draw a continuous airflow through the air passageway 42,through the aperture 130 a in the turret 110 aligned with the inlet 44of the air passageway 42, through the passageway 158 a in the cap 142,and through the aperture 150 a in the cap 142. Because the aperture 150a in the cap 142 is positioned over and aligned with the impactor 114 a,the impactor 114 a redirects the airflow as it moves through thepassageway 158 a in the cap 142. Particulate matter entrained in theairflow, particularly heavier and larger particulates, tend to respondless to the redirection of the airflow than lighter and smallerparticulates, making it more likely that heavier and larger particulatesimpinge upon the platform 134 a and become trapped in the adhesive orgel substance on the platform 134 a. As a result, particulate matterhaving a nominal size of 1 micron or less is likely to be redirectedwith the airflow around the impactor 114 a in the passageway 158 a inthe cap 142. The airflow (containing particulate matter having a nominalsize of 1 micron or less) then flows through the aperture 130 a in theturret 110 and enters the air passageway 42 via the inlet 44.

With reference to FIG. 8, The impactor assembly 38 is shown “dialed” tothe position in which the aperture 130 d in the turret 110 is alignedwith the inlet 44 of the air passageway 42. Because no impactor iscontained within the passageway 158 d in the cap 142, no particulatematter is trapped or filtered before the airflow enters the airpassageway 42. As a result, particulate matter of varying sizes ismeasured by the optical engine 46 and collected by the filter cartridge50.

With reference back to FIG. 5, upon entering the air passageway 42, theairflow passes through the optical engine 46 for real-time measurementof the amount and sizes of the entrained particulate matter, andimmediately thereafter is passed through the filter cartridge 50 tocollect samples of the particulate matter that was measured by theoptical engine 46. During the IAQ test, the results of the measurementby the optical engine 46 are displayed in real time on the displayscreen 18 (see FIG. 1) and/or can be output from the monitor 10 via adata transfer outlet located behind one or more of the plugs 30. Aftercompletion of the IAQ test, the filter cartridge 50 may be removed fromthe housing 14 as described above to send to a laboratory to performadditional or supplemental testing or analysis of the collectedparticulate matter. Alternatively, the monitor 10 may be operated duringan IAQ test using only the optical engine 46 to view in real time theresults of the measurements taken by the optical engine 46. In such amanner of operation, the filter element 54 may be omitted from thefilter cartridge 50, thereby providing a “blank” cartridge. In theillustrated embodiment, a blank cartridge may be utilized to completethe air passageway 42 without collecting or filtering particulate matterfrom the airflow. In other embodiments, the air passageway 42 could bere-configured so that the filter cartridge 50 could be removed withoutbeing replaced with a blank cartridge. Also, the monitor 10 mayalternatively be operated during an IAQ test using only the filtercartridge 50 to collect particulate matter samples, without firstmeasuring the particles using the optical engine 46. In such a manner ofoperation, the optical engine 46 may be deactivated.

While the pump 90 and optical engine 46 are functioning, the monitor 10is operable to perform additional air quality testing using the sensors166 a, 166 b and the PID 166 c. Specifically, the axial fan 178 may beenergized to draw an airflow through the inlet openings 190 in the cover34, and through the passageway 186 between the cover 34 and the PCB 182and over the sensors 166 a, 166 b and the PID 166 c. As the airflowpasses over the sensors 166 a, 166 b, the sensors 166 a, 166 b detectthe amount of carbon dioxide and toxic gases (e.g., carbon monoxide,etc.), respectively, present in the airflow and output the results ofthe measurements to the PCB 182 and ultimately to the display screen 18for real-time observation. As the airflow passes over the PID 166 c, itdetects the amount of VOCs present in the airflow and outputs theresults of the measurement to the PCB 182 and ultimately to the displayscreen 18 and/or data transfer outlet) for real-time observation.

The axial fan 178 may then discharge the airflow through the cutout 194in the PCB 182 and into the interior of the housing 14 where it maycombine with the filtered airflow exiting the outlet 98 of the pump 90.The combined airflow may then exit the interior of the housing 14 viathe outlet openings 106 in the housing 14.

After completion of an IAQ test, the impactor turret 110 may be moved(e.g., rotated) or dialed without the use of tools to the position inwhich the aperture 130 b in the turret 110 is aligned with the inlet 44of the air passageway 42 (see FIG. 6) to utilize the impactor 114 b. Torotate the turret 110, one could grasp the cap 142 and apply an amountof torque to the cap 142 sufficient to cause the raised surface 132 a todisengage the depression 133 and displace the turret 110 and cap 142upwardly against the bias of the spring 128, allowing the cap 142 andturret 110 to be rotated in a counter-clockwise direction until theraised surface 132 b falls into the depression 133 to indicate to theuser that the impactor 114 b is ready to be used. Further, the filtercartridge 50 may be replaced with a fresh cartridge 50, and another IAQtest may be immediately performed without the substantial downtimeassociated with removing an impactor and replacing it with another asrequired in some conventional IAQ monitors.

After completion of the IAQ test using the impactor 114 b shown in FIG.6, the turret 110 may be rotated or dialed to the position in which theaperture 130 c in the turret 110 is aligned with the inlet 44 of the airpassageway 42 (see FIG. 7) to utilize the impactor 114 c, the filtercartridge 50 may be replaced with a fresh cartridge 50, and another IAQtest may be immediately performed. Additional IAQ testing may beperformed in the same manner by dialing the turret 110 to the positionassociated with the aperture 130 d in the turret 110 that is notassociated with an impactor (see FIG. 8).

As shown in FIGS. 1 and 2, the monitor 10 is compact and portable so tobe carried by a user while conducting IAQ tests. Because the monitor 10is portable, IAQ testing may be easily performed by a user in differentlocations or areas of a particular testing environment, withoutconnecting the monitor 10 to bulky, substantially non-portable dataacquisition equipment.

Various features of the invention are set forth in the following claims.

1. An air quality particulate monitor comprising: a housing; anair-moving device coupled to the housing; a first air passagewaydisposed at least partially within the housing, the air-moving deviceoperable to create an airflow through the air passageway; a real-timemeasuring device positioned at least partially within the housing and influid communication with the first air passageway; and a particulatecollection device positioned at least partially within the housing andin fluid communication with the first air passageway, the collectiondevice positioned downstream of the real-time measuring device; a firstimpactor coupled to the housing, wherein the first impactor isconfigured to trap or filter particulates having a particular nominalsize or greater; and a second air passageway at least partiallycontaining therein the first impactor, the second air passagewayselectively fluidly communicable with the first air passageway.
 2. Theair quality particulate monitor of claim 1, further comprising: a secondimpactor coupled to the housing; and a third air passageway at leastpartially containing therein the second impactor, the third airpassageway isolated from the second air passageway and selectivelyfluidly communicable with the first air passageway.
 3. The air qualityparticulate monitor of claim 1, further comprising a third airpassageway isolated from the second air passageway and selectivelyfluidly communicable with the first air passageway.
 4. The air qualityparticulate monitor of claim 1, wherein the air moving device is a firstair moving device, wherein the real-time measuring device is a firstreal-time measuring device, and wherein the particulate monitor furthercomprises: a second air-moving device coupled to the housing; a secondair passageway disposed at least partially within the housing, thesecond air-moving device operable to create an airflow through thesecond air passageway; and a second real-time measuring device disposedat least partially within the second air passageway.
 5. The air qualityparticulate monitor of claim 4, wherein the second real-time measuringdevice includes at least one of a carbon dioxide sensor, a carbonmonoxide sensor, and a photoionization detector.
 6. An air qualityparticulate monitor comprising: a housing; an air-moving device coupledto the housing; a first air passageway disposed at least partiallywithin the housing, the air-moving device operable to create an airflowthrough the air passageway; a real-time measuring device positioned atleast partially within the housing and in fluid communication with thefirst air passageway; and a particulate collection device positioned atleast partially within the housing and in fluid communication with thefirst air passageway, the collection device positioned downstream of thereal-time measuring device; a first impactor coupled to the housing; anda second air passageway at least partially containing therein the firstimpactor, the second air passageway selectively fluidly communicablewith the first air passageway; wherein the first impactor is movablycoupled to the housing to be movable between a first position adjacentan inlet to the first air passageway and a second position displacedfrom the inlet of the first air passageway.
 7. The air qualityparticulate monitor of claim 6, further comprising a platform movablycoupled to the housing, wherein the first impactor is supported on theplatform.
 8. An air quality particulate monitor comprising: a housing;an air-moving device coupled to the housing; a first air passagewaydisposed at least partially within the housing, the air-moving deviceoperable to create an airflow through the air passageway; a real-timemeasuring device positioned at least partially within the housing and influid communication with the first air passageway; and a particulatecollection device positioned at least partially within the housing andin fluid communication with the first air passageway, the collectiondevice positioned downstream of the real-time measuring device; a firstimpactor coupled to the housing; and a second air passageway at leastpartially containing therein the first impactor, the second airpassageway selectively fluidly communicable with the first airpassageway; wherein the real-time measuring device includes an opticalengine.
 9. The air quality particulate monitor of claim 1, wherein theparticulate collection device includes a filter cartridge having afilter element therein.